Many types of input devices are available for performing operations in a computing system, such as a keyboard, a mouse, a pen, a trackball, a joystick, a touch sensor panel, a touchscreen, a motion controller, a voice input device, and the like. Among the various input devices, the motion controller is widely used as a controller for video games or smart TVs. The motion controller uses an accelerometer to detect its approximate orientation and acceleration, and serves an image sensor, so it can be used as a pointing device. A user of the motion controller may move the motion controller to be directed to a desired location on a screen, and/or click a button for selecting an icon or a virtual key displayed at the location.